Method of making parts for comb units and the like



July 27, 1943. Q L MOLNAR 2,325,205

METHOD OF MAKING PARTS FOR COMB UNITS AND THE LIKE Filed Aug. 1, 1940 4Sheets-Sheet 1 o L f W/WW WWW 4 Sheets-Sheet 2 C. L. MOLNAR METHOD OFMAKING PARTS FOR COMB UNITS AND THE LIKE Filed Aug. 1, 1940 July 27,1943.

a v "7O DDDDDDDD y '27} 1943- i c. L. MOLNAR 2,325,205

METHOD OF MAKING PARTS FOR COMB UNITS AND THE LIKE Filed Aug. 1, 1940 4Sheets-Sheet 3 Patented July 27, 1943 mzrnonot' MAKING Finesseoom U S-ANports of certain intricate shape characteristics from sheet metalwherein a high degreeof pre- 01510;). and permanency in the ultimateshape is desired.

The invention has further reference to the manufacturefof a multi-partcomb unitwhich constitutes the stationary hair receiving and shearingmember of a dry shaver. A comb writ of this. t e is disclosed in thePatent iNQ. 3,33 91 to. John Brueckenior Shaving simple 18 characterizedby o-ne, .part comprising an extremely thin sheet of spring steelperforated to bmvide hair reoeiying openings and cutting edges andanother partcomprising a skeleton support po ts are assembled into aunit with the thin comb plate flexed: over the arched ribs and con; foming to theshape thereof and with the marginal portions of the platefixedly secured; by clamping or interlocking directly to the supportin:frame so as toconstitute a unitary: comb structure; In the operation ofa dry shaver of is kind precision of shape of the comb structure and theuality of accurately maintaining its shape are important and highlydesired factors. These requirements are difficult to attainpartlybeeause. the comb is a replaceable unit which must coactwithotherparts on the shaver proper and Partly because the cutting efiiciency 5degendson precision intimate contact between the'outtins edges of thecomb andthe cutter. I

o myinvention at difiicult problem was encountered; in the manufactureofa multi-part comb structure or; the character described in that knownmethodsot manufacture did not provide the desired degree of accuracy anduniformity in shape or; the finished comb structure, nor permanencyof;Silo-h shape. This problem was accenmated because of the intricate shapecharacterw tel: described mith thevi mr v to: attaining greater tehsile'strength; permanen y oi, form, andeconm; in. the. cost. or. manufiactuneof. such unit.

In;v fiirtherance of, these objects my invention.

confemiilatesr certain, new and unique; manufacflur nsi en ret rism e.tine of a s me a .E

' qnitarystriictllref v Fig-.321 is'i'ar ragmentary blah View showingthe Wilda supnort =of exceptional tensile strength curacy of componentparts, improvements-in the manufactureot the comb platte -particularly mthe e ind neof h se s a n ra r.t l eoi', im o eme t ui ur of .t ecqmbsupp rti n Kalli-improved --me h ofas emb i the {comb plate and the suport g ll'fi may 'llfi ma owm "@ther ohjects and attendant advantages--eenp o db .those k l dihisart as, the inv ion o s t hmi s ood brr e ensem -said comb unit disclosed in said patent to the following descriptionwhen consideredgin connectio -wi'th the accompanying drawings, in i h? 1p p c ve V ew p rt ri dkefi War ho c u of the char ter f ns, framehaving arched supporting ribs. These scribed;

. Figs. 2 to 'i-nch sive, are views of the comb support @t-difieIeH-tstages of manufacture; Fig-s are. enlarged detai-l -;sections ta-l enone se i lines -:1 m +h e ect l o F syn 4. 1 l

F i a enlarged V w. eekineatl tudinal side ofthe combsupportlljshoodngrthe manner in; which this part is located .ona diemember during certain 1 operations, described later;

9 is a er er vevi'ew of a scheme-t plate wi th n i effl e nd e p o+tions,respective1y; i Figs- 11 .and; 12 are face ViGWS .of the comb p atshowing the-zb a-nk nei d erind gopem tions, respectively.- Fig;13-is-an enlarged ber of comb blanks on especial-grindinglarbor and agrinding wheel in grinding relation to one oithecombblanks; z i it Figs.14 and 15 are face -;v ews;v the comb blank showing additionaloperations. described later; a q l Fig. lfiiis an enlarged fragmentaryviewshowe ing' the prfordtionsat onecorner'oi the corrib plow; Figs. 17,1s, and;lesresectiondi'views ca-rec ohtliesectiofi the lit-116i He". isshowing sucde er e-shap character stics of the comb p1 hi mem i' througha; die assembly" comprising iibher tnd rower die members" which Ihavedesigriedroi ass mbimg the comb plate and support "iritoflaisectiongshoviing 311111111 are concerned that they are here shown forpurpose of illustration in connection with the comb unit aboveidentified. It will also be understood that my invention in certain ofits phases is 1 directed particularly to the'manufacture of a combunit'such as identified, or to a comb structure having at least someofthe characteristics of said comb'unit.

Referring more particularly to Figs". land 10" it will be observed thatthe comb unit is made up of a comb plate and a support therefordesignated generally 'by' reference numerals 26 and 21,1 respectively.This comb unitis a replaceable, component part of an electric drysh'av'er' such" as disclosed in the Bruecker Patent No. 22345891;

above mentioned, which'operates on 'the' 'principle covered in the'Bruecker' Patent No; 2 ,081',694, granted May "25,1937. The comb plate26' here shown embodies certain improvements'over that shown in saidBruecker Patent No. 2234,8391,

, openings 38 for holding the blank during certain manufacturingoperations. The plate is then reduced in thickness to approximately.002" in a limited area designated by 39, Fig. 12, this area beingsectioned to show grinding. In Fig. 13 is shown a special grindingfixture for. this operation. The comb blank is positionedon a rotaryfixture 4| having a supporting surface 42 con- -centric with the centerabout which the fixture rotates and receding supporting surfaces 43which receive an end portion of the blank. Retaining lugs 44 on thefixture engage in the openings 38 to holdvthe blank in the positionshown. By I proper rotative feed of the fixture with respect to a-grinding wheel 45, the area 39 will be ground to'the desired reduction.The grinding wheel is preferably faced to grind an area corresponding inwidth with that of the area 39. The grinding is done throughout thelength of thesupporting some of which' improvements are' the subjectPrior to my'inve'ntion'the comb unitexisted as a structure substantiallyin the form shown in Figs. '1 and 10, that s, characterized by a combplate of extremely thin spring steel-perforated to provide a number ofso-cal1ed fclose shaving.

areas 28 having small closely positioned hair'receivi'ng openings and aso-called long hair" cut-' tingar'ea' 29 at eache'nd having teethadapted the comb plate was clampedoninterlocked to said longitudinalmembers 3| and'32 as claimed in the patent toJohn Bruecker No.2,234,893, for Shaving implement. 'The comb unit structure here shown inwhich the comb'plate is'attached to'the longitudinalmembers of thesupport by a rivet structure-is claime'dl'insai'd- Patent No. 2,234,929,for Shaving implement. 'There' are certain. steps in-the manufacture ofsaid comb plate covered in Patent 'No. "2,182,067, granted December 5,1939, to John Bruecker, for Processof manufacturing a shaving tool. a

* Referring-now to themanufacture of thecomb plate, Figs ll to. 19inclusive: In the present, embodiment of the invention .the plate is of.004" spring steel .asdistinguished from thinner stock ofla'pproximately.002" heretofore used. I'em ploy the thicker stock in order toprovidedifferent thicknesses in the areas 28 and 29 above men tioned,.but my invention in other frespectsdoes not depend upon these'areas ofdifferent thick ne'sses. In the present embodiment the'plate is blankedto theshape shown in Fig. ll, the open in gs 31 servingfor relief'ofthe-cut hair and the surface 42 designated by the dimension 45 anditsoperation is performed without'taking the temper from the extremely thinsteel section. The fix ture 4| may be constructed to carry a series ofcomb plates for successive grinding operations. Following this the combplate is perforated in a stamping operation to provide small openings 46in the areas 28 within the thin section and teeth 41 in the thicker endareas 29; In the preferred embodiment the teeth 41 are then bent downwardly in a forming operation as shown in Fig. 18. Following this theentire under'sur'face or cutting side 48 is lapped or'honed whilethisfportion of the comb plate is flexed in an arc approximating thatwhich it occupies in cooperation with a cut-' ter; in this instance 'inthe semi-cylindrical form in which it is held on the support 28. Thislapping operation is not shown in the drawings'as it is morefully'disclosed in Patent No. 2,182,067; above mentioned; Following thisthe blank' is punched to trim oif the end' portions to the shape 4 9 andto punch rivet'openings 5! shown in dotted lines'inFig. 15.- Thecut-outs 52 and 53 register with similar shapes in thesupporting framefor functionspeculiar to' theuse of this comb unit.

Referring now to the manufacture of the sup-f porting frame, Figs; 2" to10, inclusiverflm'the the shape 54 shown'in Fig. 2-having-longitudinal'side members 55 joined by a'series of cross members'56 the number and relative relation of which corr'espondwiththe'imperfo'rate areas joining the side portions of the comb'plate. Theblank 54 is then swaged by a stamping opera tion to'provide recesses 51and rivet bosses 58,

the latter being extruded from one sidebf' the blank substantially-tothe shape shown in Fig. 8. This rivetstructure is the subject matter ofsaid Patent No. 2,234,929, above mentioned. Following this a series ofoperations"are'perfo'rmed by means of shaving dies (not shown).According to my invention these shavingfdies are'so constructed as'toremove a slight amount of stock from all edge surfaces of the blank ateach shaving operation. In the case of reducing the cross members to athin section an equal amount of material is removed 'fromfeach side ofthe member, wherebyto equalize'the shearing fbrces.

In" actual commercial practice the four "cross members intermediatethose at the extreme ends are blanked toa width of .080; The firstshaving operation reduces these cross members to a width of L044 asshown diagrammatically in and 26. The shapeoffthe .face-ofseachzplungerhead 13 conforms substantially:with th'e'sha-pe of precision and theriveting operation is performed without distortion of the parts from theultimate shape characteristics desired; Upon retraction oftthe upper diethemovablepart of-the lower -die automatically retract under theinfluenceof the springs l6 and 8 I and th i'completelyassembled combunit isifree to be removed'; v i vFollowing this the comb unit isplatedpreferably-by chrrome plating: togive it"a permanentnon-corrosivefinish." wI; The appara'tus'herein disclosed is the subjectmatter of a divisionalaapplication for patent.

wWhile I have shown: a particular embodiment of my invention, it willbe'understood that I do not wish to be limited thereto since'manymodifications may bemade, and I therefore contemplate by th -appendedclaims to cover any such modifications as fall withinthe true spirit andscope of'myinvention. i V

*Iclaim: i

The. methodsof making a precision shaped part from cold-rolled steelstock to a shape having lonlgitudinalsside members joined by end crossmembers and: intermediate cross .members, the

steps of blanking the stock to the general shape 2 terial fromo-pposite'edges of the blank by a suck 'ce'ssion of shavingdie-operations on opposite sides of said'intermediate cross members toreduce the width of said cross members to approximately'less thanone-half the'thickness of successive shaving part from sheet stock suchas cold rolled steel to a shape having'heavy sectionsof substantialwidth and thino: sectionslof a lesser width, including the steps of.blanking the stock to the general shape. described with a substantialallowan'ceof material at opposite sides of said thin sections forfinishing to a predetermined shape, stamping certain of the heavysections to provide locating parts positioned within the peripheraledges of the ultimate shape, and removing stock from the opposite sideedges of the thin sectiono'f the blank by a succession of-shaving dieoperations in each of which substantially equal amounts of stock areremoved from opposite sides of the thin sections to'reduce the width ofsaid thin sections to approximately one-half the ultimate thickness ofthe stock of said -secamount of metal from eachsideto reduce said theultimate stock and locating the "blank by means of said locating-partswhen performin said successive shaving'operations. i The method ofmaking a precision shaped part from cold rolled steel stock to a shapehavof the heavy sections toprovide locating parts positioned within theperipheral edges of the ultimate shape, and removing'stock from theopposite side 'edgesof the thin sectionsby a succession' of shavingdie'operations to reducethe width of the thin sections to approximatelyless than one-half the thickness of the stockand locatingthe blankbymeans of'said, locating curved form.

certain cross'rnembers to an ultimate Widthv approximately less thanone-half the I ultimate thickness of thesaidcross members, and bendingthe shaped support to a curved form in which the said "cross membersdescribe an arc with the narrow section of each cross member in a palnetransverse to the center axis of the curved form.

5. The method of making a supporting frame for a comb of the characterdescribed compris ing blanking out from a sheet of cold rolled steel ofapproximately .042 thickness a shape having longitudinal side membersjoined by a series of cross mernbers,stamping each side member to form aseries of rivet bosses projecting from one side spaced apartlongitudinally thereof, reducing the opposite sides of certain of thecross memhere by successive shaving die operations each of which removesa uniform amount of metal from each side to reduce the width of saidcertain cross members to approximately .018", and bending the shapedsupport to a curved form in which the cross members describe an arc withthe narrow section of each said cross member in aplane transverseto thecenter 'axis of the ,CHARLES L. OL'NAR.

